By: Jeff Davis

 

The next step was to convert a Drill/Mill to CNC. I had a good understanding of stepper motors and controllers. I needed to find a more powerful controller and motor that would do the job of running a Drill/Mill. I found a site called Camtronics. They have stepper motors and driver kits that I could order. But I kept hearing things about a company call Geckodrive. They make a set of drivers call "Gecko Drives." I posted a message to the CAD_CAM_EDM_DRO list, asking the difference between the four drives that Geckodrive sells. What I was told changed my mind about everything.

I found out that Gecko make two styles of stepper drivers and two styles of servo drivers. I thought that a servo motor was just a stepper motor with a encoder on it. I found out otherwise. Just about everyone on the group set me straight. I learned that a servo motor is a regular DC motor with an encoder on it. This servo motor has the speed and power that I really needed.

I set out to get three Gecko G320's to drive my servo system. I also found out from another great site, Home machining & CNC, that Camtronics also makes a nice controller box to hold the Geckos and sells the servo motors that work with this system. Below are some pictures of building this controller box servo system.

I got the servo kit from Camtronics. I bolted all the hardware to the sheet metal sides and bottom, then I called my friend John Jones, who is a student in electronics engineering, to wire the thing.

John on the left is working on the servo box. My cousin Dan in the middle is wiring the servo motor encoder plugs. Seth on the right is cutting wire and stripping it for John.

I'm just supplying food and drinks and waiting anxiously.

Here is the completed servo box. Everything worked just fine, once we reversed the main leads on the servo motors. I don't know why but the leads had to be changed before the motors would work.

John added a +5 volt supply to power the Gecko drives. You can see it below the blue Cap and to the right of the transformer. This is nice to have so I don't need an external power supply for the Geckos. John got the power from the Cap and stepped it down to + 5 volt. Very nice!

After John figured out the wiring of the servo box, I decided to draw up a wiring diagram for anyone who wants to build this box. It is in PDF format. I have not shown the wiring of the limit, home, or IO switches because I have not yet wired them. If and when I do I will add this to the diagram. Zoom in to this PDF file to see the wire thickness. I have a chart of wire sizes but you need to zoom in far enough to make it visible.

Servo Box Wire Diagram.

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